La qualité de l'air intérieur dans les hôpitaux

Le projet QAIHOSP s’appuie sur les résultats de l’étude de faisabilité AICHA qui présentait, pour la première fois en 2012, des données de contamination chimique de l’air intérieur d’un hôpital, l’hôpital Pontchaillou du CHU de Rennes. Cette étude a montré que la contamination était dominée par les alcools (ex. éthanol, isopranol), l’éther et l’acétone, avec une grande variabilité entre les zones étudiées. Ce projet vise donc à collecter des informations sur cet ensemble de contaminants, c’est-à-dire disposer d’une série de données suffisamment complète pour servir de base à une première évaluation de l’exposition du personnel et des patients aux différentes substances chimiques présentes dans les hôpitaux ainsi qu’aux agents biologiques aéroportés

Variation of organic carbon and nitrate with river flow within an oceanic regime in a rural area and potential impacts for drinking water production

International audienceOver the last two decades, climate change has become a major environmental and public health concern due to the increase of the mean temperature on the Earth and its consequences on extreme meteorological events such as floods and droughts. These events induce very low or very high river flows that may impair surface water quality, and therefore result in potential health impacts when used for drinking water production. The present study aims at assessing the impact of hydrologic regime on surface water quality with a particular emphasis on total organic carbon (TOC) and nitrate. Water quality data from three French rivers acquired over a 27 years period, from January 1983 to December 2009, show the influence of extreme flows. Variation in TOC and nitrate concentrations showed opposite patterns for the whole range of flow rate (from less than 10% up to more than 100% of the mean flow). Regarding fluxes, TOC increased continuously with flow rate while nitrate was stable for very high discharges. The C/N ratio expressed from TOC and nitrate concentrations showed high values for extreme flows and particularly for very low flow rates, generally in summer, where nitrate is assimilated by biomass. Considering TOC and nitrate fluxes, it is confirmed that the worst situations were encountered for very high flow rates, namely for TOC exportation during surface runoff which was related to heavy rains or floods. These findings are of great importance with regard to the adaptation for drinking water treatment in facing extreme hydrological conditions, of which the frequency is increasing with climate change

Temporal estimation with two moving objects: overt and covert pursuit

The current study examined temporal estimation in a prediction motion task where participants were cued to overtly pursue one of two moving objects, which could either arrive first, i.e., shortest [time to contact (TTC)] or second (i.e., longest TTC) after a period of occlusion. Participants were instructed to estimate TTC of the first-arriving object only, thus making it necessary to overtly pursue the cued object while at the same time covertly pursuing the other (non-cued) object. A control (baseline) condition was also included in which participants had to estimate TTC of a single, overtly pursued object. Results showed that participants were able to estimate the arrival order of the two objects with very high accuracy irrespective of whether they had overtly or covertly pursued the first-arriving object. However, compared to the single-object baseline, participants’ temporal estimation of the covert object was impaired when it arrived 500 ms before the overtly pursued object. In terms of eye movements, participants exhibited significantly more switches in gaze location during occlusion from the cued to the non-cued object but only when the latter arrived first. Still, comparison of trials with and without a switch in gaze location when the non-cued object arrived first indicated no advantage for temporal estimation. Taken together, our results indicate that overt pursuit is sufficient but not necessary for accurate temporal estimation. Covert pursuit can enable representation of a moving object’s trajectory and thereby accurate temporal estimation providing the object moves close to the overt attentional focus

Cryogenic measurement of the optical absorption coefficient in sapphire crystals at 1.064(micro)m for the Large-scale Cryogenic Gravitational wave Telescope

We have applied laser calorimetry to the measurement of optical absorption in mono-crystalline sapphire at cryogenic temperatures. Sapphire is a promising candidate for the mirror substrates of the Large-scale Cryogenic Gravitational wave Telescope. The optical absorption coefficients of different sapphire samples at a wavelength of 1.064(micro)m at 5K were found to average 90ppm/cm.Comment: 8 pages, accepted to Phys. Lett.

A decision support system for drinking water production integrating health risks assessment

The issue of drinking water quality compliance in small and medium scale water services is of paramount importance in relation to the 98/83/CE European Drinking Water Directive (DWD). Additionally, concerns are being expressed over the implementation of the DWD with respect to possible impacts on water quality from forecast changes in European climate with global warming and further anticipated reductions in north European acid emissions. Consequently, we have developed a decision support system (DSS) named ARTEM-WQ (AwaReness Tool for the Evaluation and Mitigation of drinking Water Quality issues resulting from environmental changes) to support decision making by small and medium plant operators and other water stakeholders. ARTEM-WQ is based on a sequential risk analysis approach that includes consideration of catchment characteristics, climatic conditions and treatment operations. It provides a holistic evaluation of the water system, while also assessing human health risks of organic contaminants potentially present in treated waters (steroids, pharmaceuticals, pesticides, bisphenol-a, polychlorobiphenyls, polycyclic aromatic hydrocarbons, petrochemical hydrocarbons and disinfection by-products; n = 109). Moreover, the system provides recommendations for improvement while supporting decision making in its widest context. The tool has been tested on various European catchments and shows a promising potential to inform water managers of risks and appropriate mitigative actions. Further improvements should include toxicological knowledge advancement, environmental background pollutant concentrations and the assessment of the impact of distribution systems on water quality variation

DECONbench: a benchmarking platform dedicated to deconvolution methods for tumor heterogeneity quantification

Quantifcation of tumor heterogeneity is essential to better understand cancer progression and to adapt therapeutic treatments to patient specifcities. Bioinformatic tools to assess the diferent cell populations from single-omic datasets as bulk transcriptome or methylome samples have been recently developed, including reference-based and reference-free methods. Improved methods using multi-omic datasets are yet to be developed in the future and the community would need systematic tools to perform a comparative evaluation of these algorithms on controlled data

Molecular characterization of the elicitor and analyze of partners involved in the potato Rx gene-mediated resistance to viruses in crop plants

Le gène de résistance (Rx) au virus X de la pomme de terre (PVX) code pour une molécule réceptrice qui interagit avec la protéine de capside (CP) du PVX conférant ainsi une résistance à la plante. Les mécanismes de résistance sont encore peu compris. Dans ce projet, nous nous intéressons à la caractérisation de cette interaction. Le premier objectif est de caractériser l’élicitation par la CP. Nous avons d’abord mutagénéisé deux acides aminés clés de la CP du PVX et montré que le niveau de la réponse par Rx est dépendant de l’affinité de l’éliciteur avec le récepteur. Nous montrons également que les CP de virus proches du PVX, présentant des variations naturelles de séquences, sont capables d’induire une résistance par Rx. Le second objectif est d’identifier les partenaires de cette résistance. Une collection de mutants EMS de tomates portant le gène Rx a été générée. Trois plantes présentant un défaut de résistance vis-à-vis du PVX ont été isolées et sont en cours de caractérisation.In potato, the resistance gene (Rx) encodes a protein that confers resistance against Potato virus X (PVX). The trigger of the resistance is the recognition of PVX coat protein (CP). The mechanisms of this resistance are not well understood. In this project we investigate two different aspects of this interaction. The first goal of this project is to characterize the CP elicitor. In the first approach we mutagenized key amino acids in the PVX CP and showed that the affinity between elicitor and receptor modulates the intensity of the Rx response. In the second approach we showed that other viruses related to PVX with natural sequence variations in the CP are able to induce Rx mediated resistance. The second goal of this project is to identify genes required for Rx mediated resistance a collection of EMS mutants tomato (cv Micro-Tom) carrying the Rx gene has been generated and screened for restored susceptibility to PVX. Three mutants were identified and characterized

Influence de la gravité sur la perception et l'interrception d'objets en mouvement

In order to explain Humans' success in interceptive actions of gravitationally accelerated objects, despites the low capacity of the visual system to detect it, several studies have recently suggested that gravity has been embodied in a quantitative internal model of gravity thereby permitting access to exact time-to-contact (TTC) when intercepting a free falling object. However, we may wonder if theoretical and methodological concerns in these experiments cannot call into question the effective demonstration of the existence and use of such a model. The goal of this doctoral work was to determine how our knowledge of gravity influences our perception and actions. We conducted six experimentations issued from three different paradigms, perceptive judgement, indirect interception and direct interception. Our results refute the use of a quantitative internal model of gravity, and plead in favour of the use of our knowledge of gravity as a qualitative implicit physics knowledge, which would modulate our perceptive judgements and interceptive movements but without giving access to the quantitative effects of gravity.Pour expliquer le succès des individus dans des tâches d'interception d'objets accélérés par la gravité malgré sa faible détection par le système visuel, plusieurs études ont récemment suggéré que la gravité soit internalisée dans un modèle interne de la gravité permettant l'accès au temps de contact (TTC) exact lors de l'interception d'objets en chute libre. Cependant, on peut se demander si certains problèmes méthodologiques et théoriques ne peuvent pas remettre en cause la démonstration de l'existence et l'utilisation effective d'un tel modèle. Le but de ce travail doctoral a été de déterminer de quelle manière notre connaissance de la gravité influence notre perception et nos actions. Pour cela, nous avons conduit six expérimentations issues de trois paradigmes différents, celui des jugements perceptifs, des actions d'interception indirectes et des actions d'interception directes. Les résultats obtenus infirment l'utilisation d'un modèle interne quantitatif de la gravité, et au contraire suggèrent l'utilisation de la gravité comme une connaissance implicite qualitative de la physique, qui aurait pour conséquence de modifier nos jugements perceptifs et nos mouvements d'interception sans permettre de calculer quantitativement les effets de la gravité